The Virology Laboratory will serve as the central AIDS laboratory for confirmatory testing of antiviral activity of ribozyme constructs of vector- transduced cells developed in Projects 2 and 3, and will perform the HIV- monitoring and specimen processing in the gene therapy trials of Project 4. The development and screening tests for new anti-HIV genetic expression vectors is performed by Projects 2 and 3, and Core C will assist with assays (e.g., RT and p24 assays) which facilitate this research. At the appropriate phase of this development, this Core will provide the confirmatory anti-HIV challenge experiments using multiple-strains of HIV-1. For the clinical studies, this Core will provide services for granulocyte and mononuclear fractionation of blood and marrow specimens, and will coordinate the further analyses of these specimens within the IPCP program. Importance to Overall Program. This Core provides essential quality control to the scientific and clinical projects. In addition, in providing p24 and reverse transcriptase services to the scientific projects, this laboratory increase the productivity of the scientific projects. Similarly, the laboratory provides the necessary specimen processing and evaluation of blood and bone marrow for the gene therapy trials. This core serves to increased the productivity of both scientific projects and clinical activity.